Speed correction in telegraph circuits



NOV. 21, 1944. J A SPENCER 2,363,367

SPEED CORRECTION IN TELEGRAPH CIRCUITS A Filed June 2e, 1943 ATTORNEY ',fcern'ed,v Y

The ,distributor I I has, in addition tothe' ring ing Aof . Patented Nov. 21, 1944 omc-E James Spencer, Teaneck, N. J.,=as signor to Ra-- dio Corporation of America,` a corporation of Delaware ,loclaims This'invention relates rtcl-.he'correction of* speed 'or'.iphase displacements liz i` 'rnultiplex telegraphV 'and.aniatlogousV circuits. f Agobject of the invention is toproduce amore b rushes.withQsimplified'circuits.` v Other objects of the invention 'will' appear lin the following description, reference being had'to accurate [phase or speed adjustment of distributor the drawing, vin which:

1 v.j fIjhe 'single figure of the drawing diagrammaticallyQillustrates one embodiment ofthe at the to-p'of tion, a signal graph being shown the ligure to illustratethe'phase relation. 1 Referring to the drawing, the multiplex signals transmittedv fror'na distantV pointarrivejover line L. and passthrough the coils. of relay I to ground. Itjmaybejconsidered, by way of example; that fthe Asignalsare vof the plus-and-minus type and ,that this relayis apolar relay, .thouglnfof course,

it ".y be used for 'on-andfoif signals', as will Vbe klalluparent to thoseskilled in the art.,

` 'lflhe tongue 2 ofthe relay is connected through resistor 3 to power, say the positive'termin'al' 4. 'I'he tongue v2 isbiased Ato centerl position and.

,swings` against the niark" ,contact-5 on receipt of, say, 'a positive signal and against the space contact 6 on receipt o f'a negative signal. The niark contact 5 is! connected through thecoil Aof pulse-forming relay 'I to ground.' It is. also connected to the tongue `8 of relay, normally e-ngag"ing"'contact 9, which is connected to, 's'olid`local ring I0 of a multiplexl distributor II'serving'a plurality of channels. A portion,` nly, of the dis# "tltibuto'r I I' is shown, as* the numberof channels aterial .insofar invention is conpair'of conductively connected brushesjll, Il ysweeping over ringsl andfl?. 'Ihe``distributor arm 15 also carriesa second pair of .electrically connected-brushes I8, I9 sweep 'over the signal rings I Sand `IIlfjrespectively. 'The'15ai1sj-of brushes 'II', Iland I 8, I8 are insuv .ltd 'OIIL-ehother andiromotherlpo ons he distributor arm. f 'I'he segments go'ffrmgs .y The i segments. of .theirsisnal ring 1" "arte ha "the length of thesignal pulses 20, 'asV shownfin 1,3 and ase'gmentedsignal rinfgjI4. Distributor relay 38 isenergi'zed, 4it engagesthe Contact 42 ygraph Satthe vtop ofthegureof the drawing...

Alternate segznents," as indicated at 2|, `areconnected tothe printing orfrecording apparatus (not shown) by rconductors 2 2.'j Most' of theiother alternate segments 23 of ringl'I4""may considered as-idle or deadfthough a few are used for special signalsythe purpose of which is'immate# rial as fa'r as this invention is concerned.

segmented' local ring I2 has as many segments as there are" 'segments in the signal ring I4. Every alternate segment in -ring I2 is designated as an* a segment and these are joined' together electrically. The' other alternate Segments are 24 of relay 25 and through its operating coil 26 to'ground. The segments a rare also connected to the tongue 21 of relay 28. The operating coil 29 of-relay 28 has'A one terminal connected to the positive terminal 38 of the supply source andthe otherterminal is connected to contact 3|, which cooperates with tongue 240i `relay 25. -The other contact 32 `of relay l25 isfconnected to ground. which may, for example, be the plusminus termi nal of the 'battery-source. yTongues 24 rand :33 of relay 25 are adapted to engage contacts 3 I' and 32, respectively, when its coil 26 is energizedand to 'break therewith when def-energized.

' Segments 'b of the distributor are connected to tongue 34 of relay 35 and also through its operating'coil 36to ground, as well` as' to the tongue 31 of relay 38. The coil 3'9 of relay 38 is connected between the positive terminal 40 of the supply source and contact 4I of relay 35. The

Y contact 42 of relay '38 and the contact 43y of relay 35- are connected to ground.v

When the coil 36l of relay `35 is energized, its tongues 34y and 441 engage the contacts 4I and 43, respectively. Likewise, when the coil 39 of and disengages therefrom when the coil lis deenergizedf l Y 'I'he distributor arm I5 is rotated in approximate synchronism lanjdfphase with thedistribu- .tor arm at the distant station by anyof the wellkno'wn synchronizing systems, but by Way of example'it'may be assumed tobe rotated by the rotor 45 of a synchronous motor 46, energized from a standard frequency sour'ce'll having a voltage maintained lnapproximate synchronism and'phase with that'of` the source at the distant The motor 48 is shown as a direct current mo' tor, but this again is indicative only. One brush of this motor is connected to the positive source of the supply and the other brush `is connected to one terminal of field coils 58 and 5 I. The other terminal of field coil 50 is connected to tongue 33 of relay 25 and the remaining terminal of field coil I is connected to tongue 44 of relay 35. Field coil 50 is energized oppositely to 'feld coil 5I, so that when relay 25 is operated, motor 48. rotates in one direction and when relay 35 is operated, it rotates in the` opposite direction. In both cases it operates as a'series motor, though obviously it could beconnectedtc perform the same. action asa shunt or other typeof motor.

The operation of my invention will now bef described: l

The adjustment is such that at exa-ct phase'and synchronism the center of signal' segments 2I in succession will ybe engaged by brush I9 at the center of signal pulses` 2,0.v At suchtime brush I1 Awill-engage both vsegments a and b of Yring I2, as the brushes are wider thany the separating insulation, This means that vbrush I1 will also. be in 'engagement with bothI segments aV and b.- at the start of the signal pulses 2Il` when the brush IfSfis at-the center of idle segments 23'.

Suppose, however, true phase relation is departed from, so that the distributorarm I5 is lagging the received signals. Brush I1- will then be inengagement with segment-a and out of engagement 4with the segment b when the signal pulses 28 start. When thev tongue 2 c-f relay I engages its-.mark contact 5 at the commencement of the signal marks .20, current flows through tongue 8 and contact 9, ring` II)A and brushes I.6,..I1 and.

throughcoil 25cof relay 25 to ground. This flow of current is `interruptedby energization: of; the relay 1, which opensthe circuit at. tongue 8 and contact 9; but before this circuit is opened, the

engagement of contact 3I of relay 25 closed a' holding circuitv from the positive terminal `3l) through coil 29 of relay 2.8, contact. 3|., tongue 24 and coil y26 to ground. `Relay 25; therefore remains energized after the pulse-forming relay 1 opens the circuit. Relay 28 is slow-acting due` to shunt condenser 53. and, series resistance 54 and before it operates its .switch tongue 21, a circuit is closed from the positive terminal. through the armature of motor 48, field 5D, tongue33 and contact 32 to ground. This. moves the field 41. of synchronous motor 4.6 forward, which also advances the rotor 45 and. decreasesthe lag of the distributor arm I5., When slow-acting relay 28 moves `its switch tongue 21 against its contact 55,

the coil 26 of relay 2.5 isshort-circuited and correction motor 48 is de-energized by the opening of the circuit at 32,33.r y

By way of example, relays 28` and 38. maybeadjusted to move their tongues into engagement with their contacts so `as to give. an optimum re,- lease of the armaturesof relays 25. and 35 in seventy-five milliseconds.

There lcan be only one pulseformed during. a mark period, because relay-1 remains energized throughout the mark. Relay vI is de-energized at the start of the space and the process is rerected. Thus, the speed of the distributor arm I5 will be repeatedly kicked forward until correct phase results. When this happens brush I1 will rest on both an a segment and a b segment when the marky .signal starts; This closes a circuit through both'the coils'26 `and36lof relays 25 and 35, respectively, and the short pulse cannot energize both these relay coils sulciently to move their tongues. against their contacts. Consequently, there can be no energization of the correction motor 48 s0 long as exact phase condition exists.

If the distributor arm I5 leads the received signals, the'brush I1 will be on a b segment and out of engagement with an a segment when the mark signal starts. This will energize relay 35 and close the circuit through the armature to the correction motor and field 5I vto ground. Since field 5I is energized ina reverse direction, the motor will revolve in the Opposite direction and retard the rotor 45 to decrease the lead. Timing relay 38 short-circuits coil 38 of relay 35 and stops the correcting action after the desired period of delay. This correcting action vwill be repeated until the distributor arm I5 is in exact phase with the received signals, at which time brush I.1 will engage both segment a and segment b of ring I2 at the start of the signal pulses,lwhich will prevent operation of relays 25 and 35,. as already explained.

By regulating the capacities 53 in shunt with coils 28 and 38 or the resistances 54 in circuit therewith, the timing may be so arranged as to adjust the closure of the tongues 21 and 31 with their contacts 32 and 42 after vthe desired interval of` time has elapsed and thus the length of time of the energization of the correctionl motor 48 can be adjusted 'to best operating condition.

If the brushes are slightly less` in width than the insulation` between segments a and b, a condition somewhat diflicult to meet in practice, then the brushes would never engage both segments simultaneously and there would be no current in relays 25 and 35` at true phase, but the action and results would be identical to that alreadydescribed. Also, the relays can be constructed to operate their switches on receiving the major por.. tion of the pulse energy instead of all of it. This brings them into operation with less departure from synchronism or phase. p

Having described my invention, what I claim l. In speed correction for multiplex telegraph circuits, aI speed correcting circuit, means for producing current pulses at predetermined points 1 of the signals, a control relay energized by said pulses. for closing said speed correcting circuit, a timing relay acting to de-energize the rst relay and means for delaying the de-energizing action of the timing relay.

2. Inspeed correction for multiplex telegraph circuits,` a speed correcting circuit, means for producing current pulses at predetermined points of the signals,l a control relay energized by said pulses for closing said speed correcting circuit, a timing relay having a switch, a holding circuit for said control relay connected to said switch, said control relay being. de-energized upon operation of said switch by the timing relay and means for delaying the operation of the switch by the timing relay.

3. `In speed correction for multiplex telegraph circuits, a speed correcting circuit, means for producing current pulses at predetermined points of the signals, a control relay energized by said pulses for'closing said speed correcting circuit,

a holding circuit for said relay.' a timingrelay yhaving a switch and being energized through the vswitch of the first relaya holdingcircuit for said control relay connected to said switch, said control relay beingvde-energize'd upon operation of said switch by the timing relay and means for delaying the operation yof the switch'by the tim-f ing relay.

4. In speed correction for multiplex telegraph circuits, a Aspeed correcting circuit, means for producing current pulses at predetermined points of the signal, a control relay energized by said pulses forclosing said speed correcting circuit,

a holding circuit forv said relay, atiming relay energized by the switch of thefirst relay and having g'a' switch adapted to short-circuit Saidr holding circuit to de-energize, the rst relay and means for delaying:v the operationof the second switch `by the timing relay.

5. lIn phase correction formultiplex telegraph circuits, a speed increasing circuit, a speed del creasing circuit, separate control relays having switches in said circuits, means for producing current pulses at predetermined pointsof the signals, means for causingr said 'pulses to pass` through the circuits of both of said ycontrol relays atcorrect'phase yof the signall and through `the circuit of one only at 'incorrect phase, said control relays being able tov close theirswitches only upon receiving the major part oftheenergy of said pulses and `means energizedy by'said control relays for producing vtheir defenergizajtion a predetermined time thereafter. c

6. In yphase correction for multiplextelegraph circuits, a speed increasingcircuit, a speed decreasing circuit, separate control relays-,having switches in said circuits, means for producing 'current pulses at predetermined points of the signals, means for causinggsaid pulses to pass through the circuits of both of said control relays at correct phase of the signal and through l the circuit ofy one only at incorrect phase, rsaid control relays being able Yto close their switches only upon receiving the entire energy of said `energization action of the timing relays.

8. In phase correction for multiplex telegraph f circuits, a speed increasing circuit, a speed decreasing circuit, separatey control relays having n switches in said circuits, means for vproducing current pulses at predetermined points of the signals, means .for causing said pulses to pass.

through the circuits of both of said control relays at correct phase of the signal and through the circuit of onevonly at incorrect phase,v said control relays being able to close their `switches only upon receiving the entire energy of said pulses, separate timing relays acting to de-energize the first-mentioned. relays and means for delaying the de-energization action of the timing y relays.

. 9. Inl phase correction for multiplex telegraph circuits, a speed increasingy circuit,a speed decreasing circuit, a first control relay having a switch in said speed increasing circuit,l a second control relay having a switch in said speed de-l creasing circuit, means for producing current vpulses at predetermined points` ofv the signals,

- means for causing said pulses to pass through pulses and means energized by saidfcontrol re- V lays fork producing their de-energization a predetermined time thereafter. 1

' f 7. In phase correction for multiplextelegraph f circuits, a speed increasing circuit, a speed decreasing circuit, separate control relays havingr switches in said circuits,.means for producing current' pulses at predetermined points of the the circuits of both of said control relays at cor- 'rect phase of the signal, through thev rst control relay with lagging signal phase and through the second control relay with kleading signal vphase and means energized by said controlrelays for `producing their de-energization a predetermined time thereafter.

10. In phase correction for multiplex telegraph circuits, a speed increasing circuit, a speed decreasing circuit, a riirst control relay having a switch in saidspeed increasing circuit, a second control relay having a switch in'said speed de' creasing circuit, means for producingy current pulses` at predetermined points of the signals,

vmeans for causing said pulses to pass through the circuits of both of said control relaysat correct phase of the'signal, through the rst control relay with lagging signal phase and through the second control relay with leading signal phase, separate timing relays acting to de-energize the rfirst-mentioned relays and means for delaying thede-energization' action of the timing relays.

JAMES A. SPENCER. 

